Unit 2a: Metabolic Processes - Cellular Respiration

Question 1

thermodynamics

Answer 1

The study of transformations of energy, using heat as the most convenient form of measurements of energy.

Question 2

kinetic energy

Answer 2

The energy of motion.

Question 3

potential energy

Answer 3

Energy that is not being used, but could be; energy in a potentially usable form; often called “energy of position”.

Question 4

oxidation

Answer 4

Loss of an electron by an atom or molecule; in metabolism, often associated with a gain of oxygen of a loss of hydrogen.

Question 5

reduction

Answer 5

Gain of an electron by an atom or molecule; in metabolism, often associated with a gain of hydrogen and loss of oxygen.

Question 6

oxidation-reduction reaction

Answer 6

A type of paired reaction in living systems in which electrons lost from one atom (oxidation) are gained by another atom (reduction). Termed a redox reaction for shot.

Question 7

First Law of Thermodynamics

Answer 7

Energy cannot be created or destroyed, but can only undergo conversion from one form to another; thus, the amount of energy in the universe is unchangeable.

Question 8

heat

Answer 8

A measure of the random motion of molecules; the greater the heat, the greater the motion. Heat is one form of kinetic energy.

Question 9

Second Law of Thermodynamics

Answer 9

A statement concerning the transformation of potential energy into heat; it says that disorder (entropy) is continually increasing in the universe as energy changes occur, so disorder is more likely than order.

Question 10

entropy

Answer 10

A measure of the randomness or disorder of a system; a measure of how much energy in a system has become so dispersed (usually as evenly distributed heat) that is no longer available to do work.

Question 11

free energy

Answer 11

Energy available to do work.

Question 12

endergonic

Answer 12

Describes a chemical reaction in which the products contain more energy than the reactants, so that free energy must be put into the reaction from an outside source to allow it to proceed.

Question 13

exergonic

Answer 13

Describes a chemical reaction in which the products contain less free energy than the reactants, so that free energy is released in the reaction.

Question 14

activation energy

Answer 14

The energy that must be processed by a molecule in order for it to undergo a specific chemical reaction.

Question 15

catalysis

Answer 15

The process by which chemical subunits of larger organic molecules are held and positioned by enzymes that stress their chemical bonds, leading to the disassembly of the larger molecule into its subunits, often with the release of energy.

Question 16

inorganic phosphate

Answer 16

A phosphate molecule that is not a part of an organic molecule; inorganic phosphate groups are added and removed in the formation and breakdown of ATP and in many other cellular reactions.

Question 17

autotroph

Answer 17

An organism able to build all the complex organic molecules that it requires as its own food source, using only simple inorganic compounds.

Question 18

heterotroph

Answer 18

An organism that cannot derive energy from photosynthesis or inorganic chemicals, and so must feed on other plants and animals, obtaining chemical energy by degrading their organic molecules.

Question 19

cellular respiration

Answer 19

The metabolic harvesting of energy by oxidation, ultimately dependant on molecular oxygen; carried out by the Krebs cycle and oxidative phosphorylation.

Question 20

dehydrogenation

Answer 20

Chemical reaction involving the loss of a hydrogen atom. This is an oxidation that combines loss of an electron with loss of a proton.

Question 21

nicotinamide adenine dinucleotide (NAD)

Answer 21

A molecule that becomes reduced (to NADH) as it caries high-energy electrons from oxidized molecules and delivers them to ATP-producing pathways in the cell.

Question 22

NADH dehydrogenase

Answer 22

An enzyme located on the inner mitochondrial membrane that catalyzes the oxidation by NAD+ of pyruvate to acetyl-CoA. This reaction links glycolysis and the Krebs cycle.

Question 23

aerobic respiration

Answer 23

The process that results in the complete oxidation of glucose using oxygen as the final electron acceptor. Oxygen acts as the final electron acceptor for an electron transport chain that produces a proton gradient for the chemiosmotic synthesis of ATP.

Question 24

anaerobic respiration

Answer 24

The use of electron transport to generate a proton gradient for chemiosmotic synthesis of ATP using a final electron acceptor other than oxygen.

Question 25

electron transport chain

Answer 25

The passage of energetic electrons through a series of membrane-associated electron-carrier molecules to proton pumps embedded within mitochondrial or chloroplast membranes.

Question 26

glycolysis

Answer 26

The anaerobic breakdown of glucose; this eyzme-catalyzed process yields two molecules of pyruvate with a net of two molecules of ATP.

Question 27

oxidative phosphorylation

Answer 27

Synthesis of ATP by ATP synthase using energy from a proton gradient. The proton gradient is generated by electron transport, which requires oxygen.

Question 28

ATP synthase

Answer 28

An enzyme that catalyzes the formation of ATP from the phosphorylation of ADP with inorganic phosphate, using a form of energy, such as the energy from a proton gradient.

Question 29

fermentation

Answer 29

The enzyme-catalyzed extraction of energy from organic compounds without the involvement of oxygen.

Question 30

deamination

Answer 30

The removal of an amino group; part of the degradation of proteins into compounds that can enter the Krebs cycle.

Question 31

β-oxidation

Answer 31

Th oxygen-dependent reactions where 2-carbon units of fatty acids are cleaved and combined with CoA to produce acetyl-CoA, which then enters the Krebs cycle. This occurs cyclically until the entire fatty acid id oxidized.

Question 32

myofibril

Answer 32

Long, cylindrical organelle in striated muscle cells, composed mainly of actin and myosin filaments that run from one end of the cell to the other.

Question 33

myofilament

Answer 33

A contractile microfilament,composed largely of actin and myosin, within muscle.

Question 34

myosin

Answer 34

One of the two protein components of microfilaments (the other is actin); a principal component of vertebrate muscle.

Question 35

tropomyosin

Answer 35

Low-molecular-weight protein surrounding the actin filaments of striated muscle.

Question 36

troponin

Answer 36

Complex of globular proteins positioned at intervals along the actin filament of skeletal muscle; thought of serve as a calcium-dependant “switch” in muscle contraction.

Question 37

sarcoplasmic reticulum (SR)

Answer 37

The endoplasmic reticulum of a muscle cell. A sleeve of membrane that wraps around each myofilament.

Question 38

metabolism

Answer 38

The sum of all the chemical reactions that occur in a living system (a cell or a body)

Question 39

catabolism

Answer 39

Consisting of all the destructive reactions that release free energy (exergonic reactions). Digestion and respiration are examples of catabolic processes.

Question 40

anabolism

Answer 40

Consists of all the constructive reactions that require and input of free energy and decrease the entropy of the body (endergonic reactions. Protein synthesis and photosynthesis are examples of anabolic reactions.

Question 41

activation energy

Answer 41

Energy required to start reaction.

Question 42

substrate level phosphorylation

Answer 42

The transfer of phosphate at the active site; way to get ATP.

Question 43

reaction coupling

Answer 43

Redox reactions (endergonic/exergonic, oxidation/reduction)

Question 44

reduction of NAD+

Answer 44

NAD+ is the oxidized form; NADH/NADH+H+ is the reduced form. (H+H+ to show 2 electrons meaning reduced - gain of electron)

Question 45

chemiosmosis

Answer 45

The diffusion of hydrogen ions (protons) across the biological membrane via the ATP synthase (a transport protein) due to a proton gradient that forms on the other side of the membrane. The proton gradient forms when the hydrogen ions accumulate as they are forcibly moved to the other side of the membrane by carrier proteins while the electrons pass through the electron transport chain in the membrane. Since more hydrogen ions are on the other side they tend to move back across the membrane via the ATP synthase. As they flow through energy is released which is then used to convert ADP to ATP (by a process called phosphorylation).